Assuming the controller was in /controllers/dashboard/myprofile/myfilea.php (not in a package) you would name your class

DashboardMyProfileMyFileAController

I should also mention that the concrete naming convention is to use underscores in file names. So you would probably want to call the file my_file_a.php. This wouldn't change the name of the controller though.

I don't believe there is any naming requirements for models. If you had a file: models/my_model_a.php you should be able to name the class whatever you want then load it in with